In substrate processing apparatuses using a gas phase reaction such as film deposition apparatuses or etching apparatuses, a substrate is transferred to a processing chamber, placed on a susceptor, processed, and transferred out of the processing chamber. Since a film may be formed also on the susceptor or the susceptor may be damaged during the processing, the susceptor needs maintenance works such as cleaning and coating at predetermined intervals.
If the maintenance works cannot be performed in the processing chamber, however, the susceptor needs to be taken out for the cleaning. If the processing chamber is open to the air to take out the susceptor, the throughput is considerably reduced. The susceptor therefore is preferably transferred in a manner similar to the transfer of the substrate. A mechanism for lifting up and down the substrate for the transfer, however, selectively lifts up and down the substrate, and therefore cannot be used to further transfer the susceptor after the substrate is taken out. Thus, another mechanism needs to be provided.
If the maintenance is performed at frequent intervals, the substrate together with the susceptor is taken out of the processing chamber, and after the substrate is removed, the maintenance of the susceptor is performed. In this case, the substrate needs to be placed on the susceptor or removed from the susceptor outside the processing chamber. The maintenance, however, is not needed to be performed after every processing operation.